Magnetic recording and reproduction apparatus

ABSTRACT

A magnetic recording and reproduction apparatus includes a main chassis on which a rotatable head cylinder is mounted; a sub chassis movable relative to the main chassis; a cassette holder for holding the cassette and mounting the cassette on the sub chassis; a cassette holder elevating section for moving the cassette holder up and down with respect to the sub chassis; a holder engaging section provided on the main chassis; and a main chassis engaging section provided on the cassette holder. The sub chassis is movable relative to the main chassis from a cassette mountable position at which the cassette is mountable on the sub chassis to a tape pull-out position at which the magnetic tape has been pulled out from the cassette and wound around the rotatable head cylinder. The holder engaging section and the main chassis engaging section are engaged with each other at the tape pull-out position.

This non-provisional application claims priority under 35 U.S.C.,§119(a), on Patent Application No. 2003-101255 filed in Japan on Apr. 4,2003, the entire contents of which are hereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a magnetic recording and reproductionapparatus, and in particular to a magnetic recording and reproductionapparatus in which a sub chassis is movable relative to a main chassis.

2. Description of the Related Art

A magnetic recording and reproduction apparatus includes two chassis,i.e., a main chassis and a sub chassis, for recording information to,and/or reproducing information from, a magnetic tape accommodated in acassette.

With reference to FIGS. 11, 12, 13, 14, 15, 16 and 17, a conventionalmagnetic recording and reproduction apparatus 600 will be described.

FIG. 11 shows a main chassis 400 of a conventional magnetic recordingand reproduction apparatus 600. Part (a) of FIG. 11 is a left side viewof the main chassis 400, and part (b) of FIG. 11 is a plan view thereof.

The following elements are provided on the main chassis 400: a rotatablehead cylinder 402 for recording information to, and/or reproducinginformation from, a magnetic tape, a first projection guide section 404projecting upward from the main chassis 400, and a second projectionguide section 406 projecting upward from the main chassis 400.

In FIG. 11, the elements other than the rotatable head cylinder 402, thefirst projection guide section 404 and the second projection guidesection 406 are omitted for the sake of simplicity.

FIG. 12 shows a sub chassis 500 of the conventional magnetic recordingand reproduction apparatus 600. Part (a) of FIG. 12 is a left side viewof the sub chassis 500, part (b) is a plan view thereof, and part (c) isa right side view thereof.

The following elements are provided on the sub chassis 500: a lockengaging section 502, a first guide groove 504, and a second guidegroove 506. The lock engaging section 502 is provided at a right end ofthe sub chassis 500.

In FIG. 12, the elements other than the lock engaging section 502, thefirst guide groove 504, and the second guide groove 506 are omitted forthe sake of simplicity.

FIG. 13 shows a cassette holder 550 of the conventional magneticrecording and reproduction apparatus 600. Part (a) of FIG. 13 is a leftside view of the cassette holder 550, part (b) is a plan view thereof,part (c) is a right side view thereof, and part (d) is a front viewthereof.

The cassette holder 550 includes an insertion opening 552 through whicha cassette can be inserted, and a lock lever 554 for locking thecassette holder 550 to the sub chassis 500.

The lock lever 554 and the lock engaging section 502 shown in FIG. 12are included in a locking section.

In FIGS. 11, 12 and 13, a mechanism for pulling out a tape from thecassette and winding the tape around the rotatable head cylinder 402, amechanism for driving the tape and the like are omitted.

FIGS. 14 and 15 are each a schematic view of a cassette holder elevatingsection 560 of the conventional magnetic recording and reproductionapparatus 600. The cassette holder elevating section 560 moves thecassette holder 550 upward and downward with respect to the sub chassis500. FIG. 14 shows a state where the cassette holder 550 has been movedup with respect to the sub chassis 500 by the cassette holder elevatingsection 560. FIG. 15 shows a state where the cassette holder 550 hasbeen moved down with respect to the sub chassis 500 by the cassetteholder elevating section 560.

The cassette holder elevating section 560 includes a first link 562, asecond link 564, and a spring 566.

FIGS. 14 and 15 show a left side section 500 a of the sub chassis 500shown in FIG. 12. The side section 500 a has a cam groove 500 b therein.FIG. 12 shows only a bottom section of the sub chassis 500 and does notshow the left side section 500 a.

A left side section of the cassette holder 550 has a cam groove 550 aprovided therein.

As shown in FIGS. 14 and 15, the first link 562 has a first end 562 aand a second end 562 b. The first end 562 a is slidably engaged with thecam groove 500 b, and the second end 562 b is pivotably engaged with theleft side section of the cassette holder 550.

The second link 564 has a first end 564 a and a second end 564 b. Thefirst end 564 a is slidably engaged with the cam groove 550 a of thecassette holder 550, and the second end 564 b is pivotably engaged withthe left side section 500 a of the sub chassis 500.

The first link 562 and the second link 564 are pivotably engaged witheach other at an engaging point 564 c.

The spring. 566 is extended between the first link 562 and the secondlink 564. One end of the spring 566 is connected to the second end 562 bof the first link 562, and the other end of the spring 566 is connectedto the first end 564 a of the second link 564. The spring 566 applies aforce so as to reduce the distance between the second end 562 b of thefirst link 562 and the first end 564 a of the second link 564. Thisincreases the distance between the sub chassis 500 and the cassetteholder 550, and thus the cassette holder 550 moves upward with respectto the sub chassis 500.

In the above, the cassette holder elevating section 560 provided on aleft side section of the magnetic recording and reproduction apparatus600 is described with reference to FIGS. 14 and 15. On a right sidesection of the magnetic recording and reproduction apparatus 600, amechanism similar to the cassette holder elevating section 560 isprovided.

In general, a synchronization shaft is provided for synchronizing thefirst links provided on the left side section and the right side sectionand also synchronizing the second links provided on the left sidesection and the right side section. FIGS. 14 and 15 omit thesynchronization shaft.

The cassette (not shown) is insertable at the state shown in FIG. 14where the cassette holder 550 has been moved up. When the cassetteholder 550 is pushed down from this state, the state shown in FIG. 15 isrealized.

When the cassette holder 550 is pushed down onto the sub chassis 500,the lock lever 554 (FIG. 13) is engaged with the lock engaging section502 (FIG. 12). This fixes the cassette holder 550 and the sub chassis500 to each other to some extent. FIGS. 14 and 15 omit the lock lever554 and the lock engaging section 502.

In general, the look lever 554 is pivotably provided to the cassetteholder 550. A detailed mechanism for engaging the lock lever 554 withthe lock engaging section 502 and releasing the lock lever 554 from thelock engaging section 502 is omitted from FIGS. 11 through 15. The locksection including the lock lever 554 and the lock engaging section 502is provided only on the right side section of the magnetic recording andreproduction apparatus 600.

FIG. 16 shows the magnetic recording and reproduction apparatus 600 at acassette mountable position. Part (a) of FIG. 16 is a left side view ofthe magnetic recording and reproduction apparatus 600, and part (b) is aplan view thereof.

FIG. 17 shows the magnetic recording and reproduction apparatus 600 at atape pull-out position. Part (a) of FIG. 17 is a left side view of themagnetic recording and reproduction apparatus 600, and part (b) is aplan view thereof.

FIGS. 16 and 17 omit the cassette holder elevating sections, themechanism for pulling out the tape from the cassette and winding thetape around the rotatable head cylinder 402, the mechanism for drivingthe tape and the like.

As shown in FIGS. 16 and 17, the first projection guide section 404 andthe second projection guide section 406 provided on the main chassis 400are respectively movably engaged with the first guide groove 504 and thesecond guide groove 506 provided in the sub chassis 500. Thus, the subchassis 500 is reciprocally movably guided relative to the main chassis400. In FIG. 16, the cassette holder 550 has been moved down withrespect to the sub chassis 500. The sub chassis 500 is movable relativeto the main chassis 400 from the cassette mountable position shown inFIG. 16 to the tape pull-out position shown in FIG. 17.

The magnetic recording and reproduction apparatus 600 has the followingproblems. The force at which the cassette holder 550 moves upward by thespring 566 is suppressed by the lock lever 554 and the lock engagingsection 502. However, since the locking section including the lock lever554 and the lock engaging section 502 is provided on the right sidesection of the magnetic recording and reproduction apparatus 600, thecassette holder 550 tries to move upward with respect to the sub chassis500 and the main chassis 400 on the left side section of the magneticrecording and reproduction apparatus 600. As a result, the left side ofthe cassette holder 550 goes upward from the horizontal state of thecassette holder 550. Thus, the position of the cassette in the heightdirection is not determined with respect to the sub chassis 500 and themain chassis 400.

In order to solve this problem, it is conceivable to set the cassette550 such that the left side of the cassette 550 is slightly lower thanthe right side thereof in the state where the cassette holder 550 hasbeen moved up. This is made possible by offsetting the phase between thefirst link provided on the left side section and the first link providedon the right side section of the cassette holder elevating section andalso offsetting the phase between the second link provided on the leftside section and the second link provided on the right side section ofthe cassette holder elevating section. However, this causes anotherproblem that the cassette holder 550 is tilted at the position where thecassette holder 550 has been moved up.

When the phase between the first links provided on the left side sectionand the right side section of the cassette holder elevating section andthe phase between the second links provided on the left side section andthe right side section of the cassette holder elevating section areoffset as described above, the cassette holder 550 presses the subchassis 500 downward in a state where the cassette holder 550 has beenmoved down by the variance in the phases. This force twists the subchassis 500 and the main chassis 400. As a result, the tilt precision ofthe tape guide posts for guiding the tape in the recording andreproduction state of the magnetic recording and reproduction apparatus600 is deteriorated, thus spoiling the stable running of the tape.

SUMMARY OF THE INVENTION

A magnetic recording and reproduction apparatus, for recordinginformation to, and/or reproducing information from, a magnetic tapeaccommodated in a cassette, includes a main chassis on which a rotatablehead cylinder for recording information to, and/or reproducinginformation from, the magnetic tape is mounted; a sub chassis movablerelative to the main chassis; a cassette holder for holding the cassetteand mounting the cassette on the sub chassis; a cassette holderelevating section for moving the cassette holder up and down withrespect to the sub chassis; a holder engaging section provided on themain chassis; and a main chassis engaging section provided on thecassette holder. The sub chassis is movable relative to the main chassisfrom a cassette mountable position at which the cassette is mountable onthe sub chassis to a tape pull-out position at which the magnetic tapehas been pulled out from the cassette and wound around the rotatablehead cylinder. The holder engaging section and the main chassis engagingsection are engaged with each other at the tape pull-out position.

Thus, a magnetic recording and reproduction apparatus is provided forholding the cassette holder with respect to the sub chassis and the mainchassis with high precision with certainty and by a simple structurewhile protecting the sub chassis and the main chassis by a reactionforce of the spring for moving up the cassette holder.

In one embodiment of the invention, the magnetic recording andreproduction apparatus further includes a guide section for including aprojection guide section provided on the main chassis and a guide grooveprovided in the sub chassis, the guide section guiding the sub chassisrelative to the main chassis by the projection guide section and theguide groove being engaged with each other; and the holder engagingsection and the main chassis engaging section are engaged with eachother in the state where at least one of the main chassis engagingsection and the holder engaging section is inserted through the guidegroove.

Thus, a magnetic recording and reproduction apparatus is provided forholding the cassette holder with respect to the sub chassis and the mainchassis with high precision with certainty by a simple structure withoutrequiring a large space while protecting the sub chassis and the mainchassis by a reaction force of the spring for moving up the cassetteholder.

In one embodiment of the invention, the magnetic recording andreproduction apparatus further includes a holder locking section forengaging the cassette holder and the sub chassis. The holder lockingsection is provided on a side of the magnetic recording and reproductionapparatus which is opposite, with respect to the center of the magneticrecording and reproduction apparatus, to the side where the holderengaging section and the main chassis engaging section are provided.

Thus, a high precision magnetic recording and reproduction apparatus isprovided for protecting the sub chassis and the main chassis from beingtwisted by a reaction force of the spring for moving up the cassetteholder, even when the mechanism for locking the cassette holder to thesub chassis at one side of the magnetic recording and reproductionapparatus. Such a magnetic recording and reproduction apparatus isrealized by providing a mechanism for engaging the cassette holder andthe main chassis.

As described above, in a magnetic recording and reproduction apparatus,the holder engaging section and the main chassis engaging section areengaged with each other at the tape-pull out position of the magneticrecording and reproduction apparatus.

Owing to such a structure, the present invention provides a magneticrecording and reproduction apparatus in which the cassette holder can beheld with respect to the main chassis with high precision with certaintyand by a simple structure.

Thus, the invention described herein makes possible the advantages ofproviding a magnetic recording and reproduction apparatus for holding acassette holder with respect to the main chassis with high precisionwith certainty and by a simple structure at the tape pull-out position.

These and other advantages of the present invention will become apparentto those skilled in the art upon reading and understanding the followingdetailed description with reference to the accompanying figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a left side view and a plan view of a main chassis of amagnetic recording and reproduction apparatus in one example accordingto the present invention;

FIG. 2 shows a left side view, a plan view, and a right side view of asub chassis of the magnetic recording and reproduction apparatus in oneexample according to the present invention;

FIG. 3 shows a left side view, a plan view, a right side view, and afront view of the magnetic recording and reproduction apparatus in oneexample according to the present invention;

FIG. 4 is a schematic view of a cassette holder elevating section in thestate where a cassette holder has been moved up in the magneticrecording and reproduction apparatus in one example according to thepresent invention;

FIG. 5 is a schematic view of the cassette holder elevating section inthe state where the cassette holder has been moved down in the magneticrecording and reproduction apparatus in one example according to thepresent invention;

FIG. 6 shows a left side view and a plan view of the magnetic recordingand reproduction apparatus at a cassette mountable position of themagnetic recording and reproduction apparatus in one example accordingto the present invention;

FIG. 7 shows a left side view and a plan view of the magnetic recordingand reproduction apparatus at a tape pull-out position of the magneticrecording and reproduction apparatus in one example according to thepresent invention;

FIG. 8 is a plan view of the main chassis of the magnetic recording andreproduction apparatus in one example according to the presentinvention;

FIG. 9 is a plan view of the sub chassis of the magnetic recording andreproduction apparatus in one example according to the presentinvention;

FIG. 10 is a plan view of the magnetic recording and reproductionapparatus at the tape pull-out position in one example according to thepresent invention;

FIG. 11 shows a left side view and a plan view of a main chassis of aconventional magnetic recording and reproduction apparatus;

FIG. 12 shows a left side view, a plan view, and a right side view of asub chassis of the conventional magnetic recording and reproductionapparatus;

FIG. 13 shows a left side view, a plan view, a right side view, and afront view of a cassette holder of the conventional magnetic recordingand reproduction apparatus;

FIG. 14 is a schematic view of a cassette holder elevating section ofthe conventional magnetic recording and reproduction apparatus in thestate where the cassette holder has been moved up;

FIG. 15 is a schematic view of the cassette holder elevating section ofthe conventional magnetic recording and reproduction apparatus in thestate where the cassette holder has been moved down;

FIG. 16 shows a left side view and a plan view of the conventionalmagnetic recording and reproduction apparatus at the cassette mountableposition; and

FIG. 17 shows a left side view and a plan view of the conventionalmagnetic recording and reproduction apparatus at the tape pull-outposition.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, the present invention will be described byway ofillustrative examples with reference to the attached drawings.

A magnetic recording and reproduction apparatus 300 in one exampleaccording to the present invention will be described with reference toFIGS. 1 through 10.

The magnetic recording and reproduction apparatus 300 for recordinginformation to, and/or reproducing information from a magnetic tapeaccommodated in a cassette includes two chassis, i.e., a main chassisand a sub chassis.

FIG. 1 shows a main chassis 100 of the magnetic recording andreproduction apparatus 300. Part (a) of FIG. 1 is a left side view ofthe main chassis 100, and part (b) of FIG. 1 is a plan view thereof.

The following elements are provided on the main chassis 100: a rotatablehead cylinder 102 for recording information to, and/or reproducinginformation from, a magnetic tape, a first projection guide section 104projecting upward from the main chassis 100, a second projection guidesection 106 projecting upward from the main chassis 100, and a holderengaging section 108.

In FIG. 1, the elements other than the rotatable head cylinder 102, thefirst projection guide section 104, the second projection guide section106, and the holder engaging section 108 are omitted for the sake ofsimplicity.

FIG. 2 shows a sub chassis 200 of the magnetic recording andreproduction apparatus 300. Part (a) of FIG. 2 is a left side view ofthe sub chassis 200, part (b) is a plan view thereof, and part (c) is aright side view thereof.

The following elements are provided on the sub chassis 200: a lockengaging section 202, a first guide groove 204, and a second guidegroove 206. The lock engaging section 202 is provided at a right end ofthe sub chassis 200.

In FIG. 2, the elements other than the lock engaging section 202, thefirst guide groove 204, and the second guide groove 206 are omitted forthe sake of simplicity.

FIG. 3 shows a cassette holder 250 of the magnetic recording andreproduction apparatus 300. Part (a) of FIG. 3 is a left side view ofthe cassette holder 250, part (b) is a plan view thereof, part (c) is aright side view thereof, and part (d) is a front view thereof.

The cassette holder 250 can hold a cassette 39 (FIG. 10) and thus canmount the cassette 39 on the sub chassis 200.

The cassette holder 250 includes an insertion opening 252 through whichthe cassette 39 can be inserted, a lock lever 254 for locking thecassette holder 250 to the sub chassis 200, and a main chassis engagingsection 256.

The lock lever 254 and the lock engaging section 202 shown in FIG. 2 areincluded in a locking section.

The main chassis engaging section 256 is provided on a bottom surface ofthe cassette holder 250.

In FIGS. 1, 2 and 3, a mechanism for pulling out a magnetic tape 40(FIG. 10) from the cassette 39 and winding the tape 40 round therotatable head cylinder 102, a mechanism for driving the tape and thelike are omitted.

FIGS. 4 and 5 are each a schematic view of a cassette holder elevatingsection 260 of the magnetic recording and reproduction apparatus 300.The cassette holder elevating section 260 moves the cassette holder 250upward and downward with respect to the sub chassis 200. FIG. 4 shows astate where the cassette holder 250 has been moved up with respect tothe sub chassis 200 by the cassette holder elevating section 260. FIG. 5shows a state where the cassette holder 250 has been moved down withrespect to the sub chassis 200 by the cassette holder elevating section260.

A left side section of the cassette holder 250 has a cam groove 250 aprovided therein.

FIGS. 4 and 5 show a left side section 200 a of the sub chassis 200shown in FIG. 2. The side section 200 a has a cam groove 200 b therein.FIG. 2 shows only a bottom section of the sub chassis 200 and does notshow the left side section 200 a.

As shown in FIGS. 4 and 5, the cassette holder elevating section 260includes a first link 262, a second link 264, and a spring 266.

The first link 262 has a first end 262 a and a second end 262 b. Thefirst end 262 a is slidably engaged with the cam groove 200 b, and thesecond end 262 b is pivotably engaged with the left side section of thecassette holder 250.

The second link 264 has a first end 264 a and a second end 264 b. Thefirst end 264 a is slidably engaged with a cam groove 250 a of thecassette holder 250, and the second end 264 b is pivotably engaged withthe left side section 200 a of the sub chassis 200.

The first link 262 and the second link 264 are pivotably engaged witheach other at an engaging point 264 c.

The spring 266 is extended between the first link 262 and the secondlink 264. One end of the spring 266 is connected to the second end 262 bof the first link 262, and the other end of the spring 266 is connectedto the first end 264 a of the second link 264. The spring 266 applies aforce so as to reduce the distance between the second end 262 b of thefirst link 262 and the first end 264 a of the second link 264. Thisincreases the distance between the sub chassis 200 and the cassetteholder 250, and thus the cassette holder 250 moves upward with respectto the sub chassis 200.

In the above, the cassette holder elevating section 260 provided on aleft side section of the magnetic recording and reproduction apparatus300 is described with reference to FIGS. 4 and 5. On a right sidesection of the magnetic recording and reproduction apparatus 300, amechanism similar to the cassette holder elevating section 260 isprovided.

In general, a synchronization shaft is provided for synchronizing thefirst links provided on the left side section and the right side sectionand also synchronizing the second links provided on the left sidesection and the right side section. FIGS. 4 and 5 omit thesynchronization shaft.

The cassette (not shown) is insertable at the state shown in FIG. 4where the cassette holder 250 has been moved up. When the cassetteholder 250 is pushed down from this state, the state shown in FIG. 5 isrealized.

When the cassette holder 250 is pushed down onto the sub chassis 200,the lock lever 254 (FIG. 3) is engaged with the lock engaging section202 (FIG. 2). This fixes the cassette holder 250 and the sub chassis 200to each other to some extent. FIGS. 4 and 5 omit the lock lever 254 andthe lock engaging section 202.

In general, the lock lever 254 is pivotably provided to the cassetteholder 250. A detailed mechanism for engaging the lock lever 254 withthe lock engaging section 202 and releasing the lock lever 254 from thelock engaging section 202 is omitted from FIGS. 1 through 5. The locksection including the lock lever 254 and the lock engaging section 202is provided only on the right side section of the magnetic recording andreproduction apparatus 300.

FIG. 6 shows the magnetic recording and reproduction apparatus 300 at acassette mountable position. Part (a) of FIG. 6 is a left side view ofthe magnetic recording and reproduction apparatus 300, and part (b) is aplan view thereof.

The cassette mountable position is a position of the magnetic recordingand reproduction apparatus 300 where the cassette (not shown) isinserted into the cassette holder 250 so that the cassette holder 250holds the cassette and the cassette is mounted on the sub chassis 200 inthat state.

FIG. 7 shows the magnetic recording and reproduction apparatus 300 at atape pull-out position. Part (a) of FIG. 7 is a left side view of themagnetic recording and reproduction apparatus 300, and part (b) is aplan view thereof.

The tape pull-out position is a position of the magnetic recording andreproduction apparatus 300 where the magnetic tape has been pulled outfrom the cassette and wound around the rotatable head cylinder 102.

FIGS. 6 and 7 omit the cassette holder elevating sections, the mechanismfor pulling out the tape from the cassette and winding the tape aroundthe rotatable head cylinder 102, the mechanism for driving the tape andthe like.

As shown in FIGS. 6 and 7, the first projection guide section 104 andthe second projection guide section 106 provided on the main chassis 100are respectively movably engaged with the first guide groove 204 and thesecond guide groove 206 provided in the sub chassis 200. Thus, the subchassis 200 is reciprocally movably guided relative to the main chassis100.

In FIG. 6, the cassette holder 250 has been moved down with respect tothe sub chassis 200. At the cassette mountable position shown in FIG. 6,the main chassis engaging section 256 provided on the bottom surface ofthe cassette holder 250 passes through the second guide groove 206 ofthe sub chassis 200. The holder engaging section 108 provided on themain chassis 100 is in the same plane as the second guide groove 206 ofthe sub chassis 200.

The sub chassis 200 is movable relative to the main chassis 100 from thecassette mountable position shown in FIG. 6 to the tape pull-outposition shown in FIG. 7.

As shown in FIG. 7, the main chassis engaging section 256 is provided inthe vicinity of the second projection guide section 106 when themagnetic recording and reproduction apparatus 300 is at the tapepull-out position.

When the magnetic recording and reproduction apparatus 300 is at thetape pull-out position, as shown in FIG. 7, the main chassis engagingsection 256 is engaged with the holder engaging section 108 to fix theposition of the cassette holder 250 in the up-and-down direction withrespect to the main chassis 100. Thus, the main chassis 100 and the subchassis 200 are protected against being twisted by the reaction force ofthe spring 266 for moving the cassette holder 250 upward.

Hereinafter, the main chassis 100 will be described in detail.

FIG. 8 is a plan view of the main chassis 100.

The main chassis 100 has, for example, the following elements providedthereon: a capstan 31, a capstan shaft 31 a provided on the capstan 31,a drive gear 32, a timing belt 33, and a center gear 34.

The main chassis 100 has four cam grooves 21 a, 21 b, 21 c and 21 dformed therein. A portion of the main chassis 100 along a forward end 21e is largely cut out on both sides of the drive gear 32 and the centergear 34 toward the rotatable head cylinder 102 (FIG. 10). The forwardend 21 e has an L-shaped cross-section in the thickness direction of themagnetic recording and reproduction apparatus 300. The forward end 21 ehas a certain thickness.

A motor 22 is rotatable forward and backward. A rotation force of themotor 22 is conveyed to a mode gear 27 via a motor worm 23, a connectionworm 24, and gears 25 and 26.

The mode gear 27 is rotatable with a support 27 a as the center ofrotation. A sub chassis driving pin 27 b is provided on a top surface ofthe mode gear 27. The sub chassis driving pin 27 b is engaged with thesub chassis 200 (FIG. 2), so that the sub chassis 200 is movablerelative to the main chassis 100.

A cylinder base 28 is secured to the main chassis 100 via three cylinderscrew holes 28 e. The rotatable head cylinder 102 (FIG. 10) is providedon a cylinder base 28, and is secured with three cylinder screw holes 28f which are screwed from a rear surface of the cylinder base 28.

Guide grooves 28 a and 28 b are respectively provided for guiding the Sboat 6 and the T boat 9 mounted on the sub chassis 200 when the S boat 6and the T boat 9 (FIG. 9) pull out the magnetic tape from the cassette39.

Elastic twisted coil springs 29 and 30 are secured on the main chassis100 in the state of being provided with a pressure by a prescribedforce.

The capstan shaft 31 a rotates in the state where the pinch roller (notshown) presses the tape to the capstan shaft 31 a, thereby driving thetape. A capstan gear 31 b is integrally provided with the capstan 31.

The drive gear 32 is supported at an axis thereof by a rotation shaft 32a provided on the main chassis 100. The drive gear 32 includes an uppergear 32 b and a lower gear 32 c. The timing belt 33 is extended aroundthe upper gear 32 b and the capstan gear 31 b integral with the capstan31.

The center gear 34 is supported at an axis thereof by a rotation shaft34 a provided on the main chassis 100. The center gear 34 includes anupper gear 34 b and a lower gear 34 c. The lower gear 32 c of the drivegear 32 and the lower gear 34 a of the center gear 34 are engaged witheach other.

Next, the sub chassis 200 will be described in detail.

FIG. 9 is a plan view of the sub chassis 200.

The sub chassis 200 has, for example, the following provided thereon:four tape pull-out members 2, 6, 9 and 10, a supply reel stand(hereinafter, referred to also as an “S reel stand”) 11 rotatablysupported on the sub chassis 200, and a take-in reel stand (hereinafter,referred to also as a “T reel stand”) 12 rotatably supported on the subchassis 200. The four tape pull-out members 2, 6, 9 and 10 will also bereferred to as a TR arm 2, an S boat 6, a T boat 9, and a T3 arm 10.

The cassette 39 (FIG. 10) is mountable on the sub chassis 200. Thecassette 39 is mounted from a forward end 1 e of the sub chassis 200.The cassette 39 has a general structure including a magnetic tape, asupply reel, a take-in reel, and a reel lock member for locking thesupply reel and the take-in reel.

The S reel stand 11 is engageable with the supply reel of the cassette,and the T reel stand 12 is engageable with the take-in reel of thecassette.

The TR arm 2 is pivotably supported about a support 2 a on the subchassis 200. A TR post 2 b is provided on a top surface of one end ofthe TR arm 2, and a TR arm driving pin 2 c is provided on a bottomsurface of the other end of the TR arm 2.

The T3 arm 10 is pivotably supported about a support 10 a on the subchassis 200. A T3 post 10 b is provided on a top surface of one end ofthe T3 arm 10, and a T3 arm driving pin 10 c is provided on a bottomsurface of the other end of the T3 arm 10.

An S arm 4 is pivotably supported about a support 4 a on the sub chassis200. An S arm driving pin 4 c is provided on a bottom surface of one endof the S arm 4, and an S link pin 4 b is provided on a top surface ofthe other end of the S arm 4.

An S link 5 is pivotably attached to the S link pin 4 b at one end ofthe S link 5. The S boat 6 is pivotably attached to the other end of theS link 5 via a boss 6 b.

A T arm 7 has substantially the same structure as that of the S arm 4.Specifically, the T arm 7 is supported to be pivotable about a support 7a on the sub chassis 200. A T arm driving pin 7 b is provided on abottom surface of one end of the T arm 7, and a T link pin 8 a isprovided on a top surface of the other end of the T arm 7.

A T link 8 is pivotably attached to the T link pin 8 a at one end of theT link 8. The T boat 9 is pivotably attached to the other end of the Tlink 8 via a boss 9 b.

The S boat 6 has an S roller post 6 a provided thereon for guiding themagnetic tape, and the T boat 9 has a T roller post 9 a and a T1 post 9c provided thereon for guiding the magnetic tape.

As described above, all the tape pull-out members 2, 6, 9 and 10 areprovided on the sub chassis 200.

The S reel stand 11 and the T reel stand 12 are supported so as to berotatable about a shaft 11 a and a shaft 12 a, respectively. A gearportion 11 b is provided around an outer circumference of the S reelstand 11, and a gear portion 12 b is provided around an outercircumference of the T reel stand 12. The S reel stand 11 is engagedwith a supply reel of the cassette 39 (FIG. 10) and the T reel stand 12is engaged with a take-in reel of the cassette 39 when the cassette ismounted on the sub chassis 200. This engagement allows the magnetic tapeto be taken in.

A brake band (TR band) 3 for controlling the tension of the magnetictape while the magnetic tape is running is wound around the S reel stand11. One end of the TR band 3 is supported about a pivotable member 2 dof the TR arm 2, and the other end of the TR band 3 is supported about apivotable member 3 a on the sub chassis 200. While the magnetic tape isrunning, a load acts on the S reel stand 11 via the TR band 3 by a forceof a TR spring 2 e attached to the TR arm 2.

In a sub chassis adjusting plate 1 b, a groove 1 a is formed. The subchassis adjusting plate 1 b is secured to the sub chassis 200 by a screw(not shown). The sub chassis 200 has a lengthy hole 1 c and a circularhole 1 d communicated with the lengthy hole 1 c at an end of the lengthyhole 1 c opposite to the forward end 1 e.

FIG. 10 is a plan view of the magnetic recording and reproductionapparatus 300 at the tape pull-out position.

The magnetic recording and reproduction apparatus 300 includes the subchassis 200 on which the cassette 39 is mountable and the main chassis100 having the rotatable head cylinder 102 mounted thereon.

The sub chassis 200 accommodates the supply reel stand 11 and thetake-in reel stand 12 respectively engageable with the supply reel andthe take-in reel in the cassette 39. The main chassis 100 accommodatesthe capstan 31 for driving the magnetic tape 40.

The idler 35 is supported by the main chassis 100 at an axis thereof,and is driven by the rotation of the capstan shaft 31 a. The idler 35 isengaged with the supply reel stand 11 and the take-in reel stand 12 torotate the supply reel stand 11 and the take-in reel stand 12.

At the tape pull-out position, the tape pull-out members 2, 6, 9 and 10pull out the magnetic tape 40 from the cassette 39 accommodating thesupply reel and the take-in reel, and winds the magnetic tape 40 aroundthe rotatable head cylinder 102 over a prescribed angle. Thus, at leastone of information recording to, and information reproduction from, themagnetic tape 40 is performed.

The main chassis 100, the sub chassis 200, and the magnetic recordingand reproduction apparatus 300 described in detail with reference toFIGS. 8, 9 and 10 merely represents one example of the presentinvention. The present invention is not limited to the structure shownin FIGS. 8, 9 and 10.

In FIGS. 8, 9 and 10, the projection guide sections, the guide grooves,the holder engaging section, the main chassis engaging section, and thecassette holder are not shown for the sake of simplicity.

As described above, according to the present invention, the holderengaging section 108 is provided on the main chassis 100, and the mainchassis engaging section 256 is provided on the cassette holder 250. Atthe tape pull-out position of the magnetic recording and reproductionapparatus 300, the main chassis engaging section 256 and the holderengaging section 108 are engaged with each other in the state where themain chassis engaging section 256 is inserted through the second guidegroove 206 of the sub chassis 200. The holder engaging section 108 andthe main chassis engaging section 256 are provided at the side oppositeto the side where the lock lever 254 and the lock engaging section 202are provided. Therefore, in the magnetic recording and reproductionapparatus 300 according to the present invention, the cassette holder250 can be held with respect to the sub chassis 200 and the main chassis100 with high precision with certainty and by a simple structure withoutrequiring a large space, and the main chassis 100 and the sub chassis200 are protected against being twisted by the reaction force of thespring for moving the cassette holder 250 upward.

In the above example, the locking section of the cassette holder 250 isprovided on the right side section of the magnetic recording andreproduction apparatus 300, and the holder engaging section 108 and themain chassis engaging section 256 are provided on the left side sectionof the magnetic recording and reproduction apparatus 300. Alternatively,the locking section of the cassette holder 250 may be provided on theleft side section of the magnetic recording and reproduction apparatus300, and the holder engaging section 108 and the main chassis engagingsection 256 may be provided on the right side section of the magneticrecording and reproduction apparatus 300.

In the above example, the main chassis engaging section 256 and theholder engaging section 108 are engaged with each other in the statewhere the main chassis engaging section 256 is inserted through thesecond guide groove 206 of the sub chassis 200. The present invention isnot limited to such a structure. The main chassis engaging section 256and the holder engaging section 108 may be engaged with each other inthe state where at least one of the main chassis engaging section 256and the holder engaging section 108 is inserted through the guidegroove. Alternatively, an opening may be provided in the sub chassis 200other than the guide groove, and the main chassis engaging section 256and the holder engaging section 108 may be engaged with each other inthe opening. The main chassis engaging section 256 and the holderengaging section 108 may be engaged with each other without providing anopening in the sub chassis 200.

In the above example, one holder engaging section 108 and one mainchassis engaging section 256 are provided. The present invention is notlimited to such a structure. A plurality of holder engaging sections anda plurality of main chassis engaging sections may be provided.

In the above example, the holder engaging section 108 and the mainchassis engaging section 256 are respectively provided on a bottomsection of the main chassis 100 and a bottom section of the cassetteholder 250. Alternatively, the holder engaging section 108 and the mainchassis engaging section 256 may be provided on a side section of themain chassis 100 and a side section of the cassette holder 250.

According to the present invention, as described above, the holderengaging section and the main chassis engaging section are engaged witheach other when the magnetic recording and reproduction apparatus is atthe tape pull-out position. Thus, the magnetic recording andreproduction apparatus can hold the cassette holder with respect to themain chassis with high precision with certainty and by a simplestructure without requiring an excessively large space.

Various other modifications will be apparent to and can be readily madeby those skilled in the art without departing from the scope and spiritof this invention. Accordingly, it is not intended that the scope of theclaims appended hereto be limited to the description as set forthherein, but rather that the claims be broadly construed.

1. A magnetic recording and reproduction apparatus for recordinginformation to, and/or reproducing information from, a magnetic tapeaccommodated in a cassette, the magnetic recording and reproductionapparatus comprising: a main chassis on which a rotatable head cylinderfor recording information to, and/or reproducing information from, themagnetic tape is mounted; a sub chassis movable relative to the mainchassis; a cassette holder for holding the cassette and mounting thecassette on the sub chassis; a cassette holder elevating section formoving the cassette holder up and down with respect to the sub chassis;a holder engaging section provided on the main chassis; and a mainchassis engaging section provided on the cassette holder; and a guidesection for including a projection guide section provided on the mainchassis and a guide groove provided in the sub chassis, the guidesection guiding the sub chassis relative to the main chassis by theprojection guide section and the guide groove being engaged with eachother; wherein: the sub chassis is movable relative to the main chassisfrom a cassette mountable position at which the cassette is mountable onthe sub chassis to a tape pull-out position at which the magnetic tapehas been pulled out from the cassette and wound around the rotatablehead cylinder; the holder engaging section and the main chassis engagingsection are engaged with each other at the tape pull-out position, andthe holder engaging section and the main chassis engaging section areengaged with each other in the state where at least one of the mainchassis engaging section and the holder engaging section is insertedthrough the guide groove.
 2. A magnetic recording and reproductionapparatus according to claim 1, further comprising a holder lockingsection for engaging the cassette holder and the sub chassis, whereinthe holder locking section is provided on a side of the magneticrecording and reproduction apparatus which is opposite, with respect tothe center of the magnetic recording and reproduction apparatus, to theside where the holder engaging section and the main chassis engagingsection are provided.